refectory

As a noun refectory

is a dining-hall especially in an institution such as a college or monastery.

As an adjective undefined is

lacking a definition or value.

As nouns the difference between refectory and cafeteria

is that refectory is a dining-hall especially in an institution such as a college or monastery while cafeteria is a restaurant in which customers select their food at a counter then carry it on a tray to a table to eat.

As nouns the difference between taxonomy and refectory

is that taxonomy is the science or the technique used to make a classification while refectory is a dining-hall especially in an institution such as a college or monastery.